Field of the Invention
The present invention relates to an article of manufacture. In particular, an electronic device for routing signals such as video signals includes a primary crosspoint switch and a redundant crosspoint switch.
Discussion of the Related Art
Signal routers typically include switches that can route signals from a particular input to one or more outputs. For example, the signal at router input 1 might be reproduced on router outputs 8 and 16. Core technologies enabling these devices include matrix switching technologies including crosspoint switches.
Digital signal routers are commonly used to manage transport of video signals such as broadcast video. These routers may be used continuously or infrequently, and they may support mission critical applications such as a master control room (“MCR”) application or non-mission critical applications such as an off-line studio mixing application.
Digital video router designers and purchasers recognize the differing demands placed on routers. For example, routers provisioning applications such as remote sessions and backup routing may typically have available service intervals during which maintenance may be performed. However, routers provisioning other applications may have no service intervals. These mission critical routers without service intervals frequently support live feeds as compared with devices in applications where router failure does not affect a live feed, for example a router in a head-end back-up path. Varying demands have led to some video router product differentiation with hardened, high-reliability devices going to mission critical applications in 24/7 service without service intervals and less sophisticated devices going to less demanding applications.
In high-reliability devices, redundancy commonly provides fail-over protection preventing loss of service, while modularity with hot-swappable parts enables fail-over protection to be restored with only a short term service interruption. These 24/7 class video routers are often referred to as “modular routers” because of their ability to quickly exchange selected components or aggregations of components such as those assembled on a printed circuit board mated with other router electronics via a plug-in connector.
Unlike modular routers continuously serving live feeds, so called “compact” routers in non-mission critical applications typically dispense with high levels of redundancy and modularity. Rather, compact routers that fail are usually swapped out or removed from service during an out-of-service repair period. And, unlike modular routers, the electronic components of a compact router may be found on a single printed circuit board that is securely fastened to a router chassis.
Digital video routers commonly utilize a serial digital interface (SDI), a family of digital video interfaces standardized by SMPTE (The Society of Motion Picture and Television Engineers). For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video.